Abstract:
An H-bridge control circuit comprises an input stage, comparator stage, inverter stage. The operation of the H-bridge can be controlled by a single analog input signal provided by a feedback stage. Shoot-through protection is provided for the H-bridge circuit through the inclusion of a dead gap determined by inputs to the comparator stage. The dead gap can be adjusted, allowing for adjustment of the precision operation of the load. The H-bridge can be used to drive a bi-directional load such as, for example, a Peltier conditioner.
Abstract:
A multichannel fluorosensor includes an optical module and an electronic module combined in a watertight housing with an underwater connector. The fluorosensor has an integral calibrator for periodical sensitivity validation of the fluorosensor. The optical module has one or several excitation channels and one or several emission channels that use a mutual focusing system. To increase efficiency, the excitation and emission channels each have a micro-collimator made with one or more ball lenses. Each excitation channel has a light emitting diode and an optical filter. Each emission channel has a photodiode with a preamplifier and an optical filter. The electronic module connects directly to the optical module and includes a lock-in amplifier, a power supply and a controller with an A/D converter and a connector. The calibrator provides a response proportional to the excitation intensity, and matches with spectral parameter of fluorescence for the analyzed fluorescent substance.
Abstract:
A UV absorption spectrometer includes a housing, a controller, and a sensor unit including an. ultraviolet light source, an analytical area in an analytical cell or in running water or gaseous medium, and an UV wavelength separator including a UV detector. An ultraviolet light in a wavelength range of 200-320 nm emits from the light source through the analytical area to the wavelength separator, and the controller transforms output signals from the UV detector into absorbance values or optical densities for two or more wavelengths in the wavelength range, calculates differences of said absorbance values or optical densities, determines a concentration of a chemical in the solution with calibration constants found for a known concentration of the chemical and said differences of said absorbance values or optical densities.
Abstract:
A UV absorption spectrometer includes a housing, a controller, and a sensor unit including an ultraviolet light source, an analytical area in an analytical cell or in running water or gaseous medium, and an UV wavelength separator including a UV detector. An ultraviolet light in a wavelength range of 200-320 nm emits from the light source through the analytical area to the wavelength separator, and the controller transforms output signals from the UV detector into absorbance values or optical densities for two or more wavelengths in the wavelength range, calculates differences of said absorbance values or optical densities, determines a concentration of a chemical in the solution with calibration constants found for a known concentration of the chemical and said differences of said absorbance values or optical densities.
Abstract:
Embodiments of the invention provide devices and methods for measuring fluid volume. Devices according to some embodiments include a chamber, having a pair of gears rotatably mounted therewithin. Fluid flow through the chamber causes rotation of the gears, such that each rotation and/or partial rotation results in a known volume of the fluid passing through the chamber. An optical sensor positioned outside of the chamber, can view the rotating gears through a substantially transparent chamber wall. The optical sensor can view an optical characteristic of one or both of the gears, and based upon this data, fluid volume, flow rate, and/or flow direction can be determined. Devices and methods disclosed herein can provide for improved preci-sion in fluid flow meter measurement. In addition, the devices and methods used herein can be more durable and easier to fabri-cate than previously known positive displacement flow meters.
Abstract:
A UV absorption spectrometer includes a housing, a controller, and a sensor unit including an ultraviolet light source, an analytical area in an analytical cell or in running water or gaseous medium, and an UV wavelength separator including a UV detector. An ultraviolet light in a wavelength range of 200-320 nm emits from the light source through the analytical area to the wavelength separator, and the controller transforms output signals from the UV detector into absorbance values or optical densities for two or more wavelengths in the wavelength range, calculates differences of said absorbance values or optical densities, determines a concentration of a chemical in the solution with calibration constants found for a known concentration of the chemical and said differences of said absorbance values or optical densities.
Abstract:
Embodiments of the invention provide devices and methods for measuring fluid volume. Devices according to some embodiments include a chamber, having a pair of gears rotatably mounted therewithin. Fluid flow through the chamber causes rotation of the gears, such that each rotation and/or partial rotation results in a known volume of the fluid passing through the chamber. An optical sensor positioned outside of the chamber, can view the rotating gears through a substantially transparent chamber wall. The optical sensor can view an optical characteristic of one or both of the gears, and based upon this data, fluid volume, flow rate, and/or flow direction can be determined. Devices and methods disclosed herein can provide for improved precision in fluid flow meter measurement. In addition, the devices and methods used herein can be more durable and easier to fabricate than previously known positive displacement flow meters.
Abstract:
A UV absorption spectrometer includes a housing, a controller, and a sensor unit including an. ultraviolet light source, an analytical area in an analytical cell or in running water or gaseous medium, and an UV wavelength separator including a UV detector. An ultraviolet light in a wavelength range of 200-320 nm emits from the light source through the analytical area to the wavelength separator, and the controller transforms output signals from the UV detector into absorbance values or optical densities for two or more wavelengths in the wavelength range, calculates differences of said absorbance values or optical densities, determines a concentration of a chemical in the solution with calibration constants found for a known concentration of the chemical and said differences of said absorbance values or optical densities.